Cab-signal system.



R. J. HEWETT.

CAB SIGNAL SYSTEM. APPLICATION FILED JAN. 5. 1915.

Patented June 12, 191?.

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ROBERT J'. HEWETT, OF WESTFIELD, NEW JERSEY.

CAB-SIGNAL SYSTEM.

Specification of Letters Patent.

Patented June 112, 1917.

Application filed January 5, 1916. Serial No. 70,382.

To all whom it WMLLI/ concern:

Be it known that I, ROBERT J. Hnwnrr, a citizen of the United States, residing at \Vestfield, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Cab-Signal Systems, of which the following is a full, clear, and exact description.

This invention relates to railway signal systems and more specifically to the systems in which the signal indications are given in the cab of a car or train. The primary ob ject of the invention is to provide a cab signal system which is controlled by a simple arrangement of circuits both in the cab and along the trackway, which may be installed at a low cost and whichgives the same information to the engineer as are now given by the usual types of roadside or track sig nals.

As is well known, the usual railway signal system comprises a trackway divided into blocks with home and distant roadside sig nals defining the block limits. The home and distant signals usually have two indications, one to indicate danger and the other clear and when the engineer approaches a distant signal set to danger, he understands thereby that he is to proceed at cantion, likewise when he approaches a home signal set to stop or danger he is ad vised that he is to stop his train and comply with the rules of the road covering such conditions. It is also well known that in such signal systems, the recent developments have been to positively move the movable roadside signal to its safety indicating position so that in case of a failure of the circuits controlling the signals, the roadside signal will immediately resume a danger indicating position. In other words, the presence of a train upon a block in advance, or certain of the blocks in advance, or a failure of the signaling system will each give a danger indication. i

This invention aims to provide a cab sig nal system which fulfils all of these conditions and yet gives a single positive signal indication in the cab thereby simplifying both the cab signal circuits and the circuits along the trackway for controlling the same.

The single positive signal indication which is given in the cab is a proceed or a safety ind cation and the failure to receive such an indication is to be regarded the equivalent of the receipt of a danger nal. The signal indication in the cab must therefore be interpreted according to the position of the train or trains on the trackway or in other words, in the light of visible symbols or signals along the trackway, which define the block limits. Such symbols should correspond in location to the ordinary home and distant roadside signals and in the preferred form of the invention immovable masts or markers positioned at the same points, as are the usual movable home and distant signals, are utilized, although if desired the system may be used in connection with the usual railway signal system having movable semaphore arms or their equivalents defining the home and distant positions of a train with respect to a given block. If the cab signal indication is given as the train approaches such home and distant markers or signals and if a positive indication is received in the cab on approaching either a home or distant marker, the en gineer is informed that it is safe for him to proceed under full speed. If, however, no signal is given in the cab as the train approaches a distant marker or signal, then the engineer knows that he is to proceed at caution. Likewise the failure to receive a signal upon the approach of a home .marker or signal is understood by the engineer as a signal for him to stop his train. Therefore,'b v the use of a single positive indication within the cab, the engineer receives the same information as he would receive from movable roadside signals. The system maytherefore be used in two ways, either as a check upon movable roadside signals, or

.entirely independent of the same, in which case immovable masts or markers are used, the latter being the preferred form of the invention due to its simplicity and comparatively low cost at which it may be installed.

Since the failure to. receive a signal is understood as a danger or caution signal depending upon the position of the train, the cab and track circuits are so arranged that a failure or break in such circuits will result in a danger or caution signal being given. More specifically stated, this means that the cab and track circuits are normally open circuits and when closed give a positive indication.

The invention may also be understood from the railway signal system embodying the features of my invention which will now be described and the novel features of which will be pointed out in the appended claims, and in the accompanying drawings:

The figure is a diagrammatic view of a portion of a railway signal system embodying the features of the invention.

As is the usual practice, the trackway is divided into blocks and in the specific construction shown, each block is divided so as to include one or more lengths of track sections which are insulated from each other and from the sections of adjacent blocks. In the drawings the track sections have been designated 9, 1.0, 11, 12 and 13, sections 9 and 10, and 11 and 12,1'cspectively, forming complete blocks, while the section 13 forms a portion of a third block which is only partially shown. In accordance with the pre'it'erred form of my invention, the block limits are defined or rendered visible to the engineer by stationary masts or markers comprising arms mounted on posts or poles similar to the manner in which the usual movable semaphore arm is supported. In the drawings, these markers have been designated 15, 16, 17 and 18 and are positioned along the trackway at points corresponding to the positions normally occupied by the movable roadside signals; that is, the marl:- ers 15 and 17 occupy QOSltlOIlS usually occupied by distant signals and the markers 16 and 18 correspond tohome signals. Arranged to the rear of each marker is a contact rail which forms a part 01 a track signal circuit, the contact rail for the distant marker 15 being designated 110, the one for the home marker 16, 35, and the one for the distant marker 17, 120. The cab signaling circuit is of the simplest nature and is adapted to give a single signal indication which is for the train to proceed. The cab is represented by the dotted inclosure on the left hand side of the figure and the cab thus represented is intended to be in a position in which its contact shoe 100, forming apart of the cab signal circuit is engaged with the contact rail 110, the cab signal circuit passing from the shoe 100, wires 101 and 102 to audible signal 103 and wires 104, 105 to the wheel 106 to track rail 118. The track signal circuit is energized by battery 114, the circuit passing from contact rail 11 0, wire '111, contact 112, wire 113 to battery 114 through wire 115,

contact 116, wire 117 to track rai-l 118,

whereby when the contact shoe 1'00 engages the contact rail 110, the circuit will be closed through the audible signal 103. If desired, a visible signal 108 may also be utilized which is connected in parallel with the audible signal 103 by wires 107 and 109.

In the same manner, when contact shoe 100 engages contact rail '35, the cab signal circuit will be closed through battery 39 which energizes both the contact rail 35 and track rail 43 through the following circuit, contact rail 35, wire 36, contact 37, wire 38, battery 39, wire 40, contact 41, wire 42 to track rail 43. In the same manner track rail 128 and contact rail 120 of track section 11 is connected to battery 124 through wire 121, contact 122, wire 123, battery 124, wire 125, contact 126 and wire 127; and track rail 75 of track section 12 and its corresponding contact rail '67 is connected directly to battery 71 through wire 68, contact '69, wire 70, battery 71, wire 72, contact 73 and wire 74.

Each of the track sections is provided with a track battery and relay which have been designated B, R 13, R B R and B R corresponding to track sections 10, 11, etc. There is corresponding to each distant marker a distant line relay which have been designated L L etc., corresponding to markers 15, 17, etc. There is also corres 'ionding to each home marker a home line relay which have been designated L, L, etc., corresponding to home mark ers 16, 18, etc.

The track signal circuit including contact rail 110 and battery 114, is controlled by the distant line relay L which controls the contacts 112 and 116 included in this circuit. The distant line relay L is ineluded in a circuit with a battery 26, the circuit starting from relay L through wire 21, contact 22 controlled by track relay R wire 23, contact 24 controlled by home line relay L wire25, battery 26, wire 27, contact '28 controlled by home line relay L wire 29, contact controlled by track relay R wire "31 to relay L. The track signal circuit including contact rail 110 is therefore controlled by the track relay R and the home line relay L The home line relay is in turn controlled by a circuit passing through battery 49, which circuit is controlled by track relays R and R, the circuit passing through home line relay L wire 44, contact controlled by track relay R, wire 46, contact 47 controlled by track relay R wire 48, battery 49, wire contact 51 controlled by track relay R wire '52, contact 53 controlled by track relay R wire 54, back to the home line relay L. It will therefore be seen that the closing of track signal circuit at the contacts 112 and 116 is controlled by track relays R, R and B so that the presence of .a train in any of the track sections 10, 11 and 12 will prevent the closing the cab signal circuit when the contact shoe 100 engages the contact rail 11 -0.

The track signal circuit including the contact rail '35 is controlled by the home line relay L through the contacts 37 and 41, and as previously traced, the home line relay L is controlled by track relays R and It so that the presence of a train in track sections 11 and 12 will prevent the giving of a signal when the shoe 100 is in contact with the contact rail 35.

The circuit for the contact rail 120 is controlled by the distant linerelay L", the circuit for this relay passing through Wire 56, contact 57 controlled by track relay R wire 58, contact 59, controlled by home line relay L wire 60, battery 4:9, wire 50, wire 61, contact 62 controlled by home line relay L wire 63, contact 64 controlled by track relay R wire 65 to distant line relay L. The circuit traced is therefore controlled by track relay R and home line relay L and the circuit for home line relay 18 passes from this relay through wire 81, contact 82 controlled by track relay R wire 83, where the circuit would be continued and corn trolled by the track relay of the track section immediately in advance, and would return through wire 89, contact controlled by track relay R, wire 91 to the home line relay L In other words, the circuits through contact rail 120 which engaged as the train approaches the distant marker 17 is controlled in all respects similar to the manner in which the circuit to the contact rail 110 is controlled; that is, the presence of a train upon track section 12, 13 and the section immediately in advance thereof, will prevent a signal from being given as the train approaches the distant marker 17. In the same manner, the track signal circuit including contact rail 67 and battery 71 is controlled by the track relay R and the relay of the block immediately in advance, similarto the manner in which the circuit for the contact rail 35 to the rear of home marker 16 is controlled by a train in either of the block sections 11 and 12.

It is believed that with this description the circuits will be clear and the operation of the system will now be described by as suming the movement of an east bound train over the several train sections 9, 10,11, 12 and 13. As is shown in the drawing, the engine is in the position it occupies when it is approaching the distant marker 15; that is, with its contact shoe on the contact rail 110. Since none of the track sections in'advance of the train are occupied,

65 and a signal will be given in the cab as the &

engine approaches the distant marker 15, which signal will be an indication to him to proceed at full speed, with the expectation of receiving a second clear signal as he approaches the home marker 16. In the same manner, as the train approaches the home marker 16, contact shoe will engage contact rail 35 closing the cab signal circuit through battery 39 and since track sections 11 and 12 are still free, track relays R and R will remain energized to maintain the home line relay L energized, which controls the con tacts 37 and 41 in the track signal circuit for the home marker 16. The engineer will therefore, as he approaches the home marker 16, receive a second clear indication which informs him that the sections 11 and 12 are clear. 'As the train approaches the distant marker 17, the contact shoe will engage contact rail 120, and as before a clear signal will be received indicating to the engineer that track sections 12, 13 and the next section immediately in advance thereof is clear, and that he may proceed to a home marker 18 at which point he may expect to receive a second clear signal.

Assuming that a train is in any of the track sections 10, 11 and 12 and that a second train is approaching the distant marker 15, the presence of a train in any of these track sections will short-circuit one of the track batteries 13 B or B and the result is that one of the track relays R R or R is de'e'nergized and as described the deenergization of any of these track relays will open the circuit to the distant line relay L which will open the track signal circuit to the contact rail 110 at contacts 112 and 116. No signal will therefore be received in the cab, informing the engineer that there is a train in the block composed of track sections 11 and 12 and that he should proceed with caution until he reaches the home marker 16, where if there is a train. present in either of the block sections 11 and 12, the track signal circuit through battery 39 which is controlled by the home line relay L will be open and prevent a clear or proceed signal from being given. It should be evident that if there is a train in track section 10, the engine would not be approaching the distant marker 15, since to do so, the engineer would have to ignore the stop signal, which he would have received at the home marker to the rear of distant marker 15. The failure to receive a safety signal as the train approaches marker 16, will therefore inform the engineer that he should stop his train in accordance with the standard rules of railway signaling and only advance after he has complied with these rules. i

It should be noted that in the system of signaling described, there is no positive stop or caution signal and the absence of the receipt of a signal in the cab is regarded and must be taken as the stop or caution signal, depending upon the position of the car or train on the trackway.

This system of signaling is also important because it permits extremely simple cab signal circuits and track signal and control circuits to be used. In so far as I am aware, it is novel with me to provide a cab signal system in which the signal indication in the cab must be interpreted with respect to the position of the train along the trackway, as well as to provide a signal system in which the failure to receive a cab signal or indication must be taken into account, and it is my intention to cover this feature broadly, irrespective of the system of track signal and control circuits employed, as it is obvious that various other forms of circuit arrangements may be employed, the essential feature being that as the engine or cab approaches the home or distant marker or signal, a positive indication be given if the trackway is clear for a predetermined distance in advance. The system described is also of importance for the reason that a break in the track signal or control circuits, or failure of current in them, will prevent a positive signal indication from being given. This is in accordance with the usual practice of roadside signaling and also in accordance with the long established practice of stall and tablet signaling where the posses sion of a staii or tablet by the engine man is a proceed signal and the absence of such a stall or tablet is :a stop signal.

I claim:

1. In a railway signal system, a trackway divided into blocks, means for indicating the home and distant positions along the trackway with respect to :each block, a cab signaling mechanism on the cab adapted to give a single indication, and means along the trackway for actuating said signaling mechanism on the cab when the car or train approaches a home or distant position and the block is clear.

2. In a railway signal system, a trackway divided into blocks, means defining home and distant positions along the trackway with respect to each :block, a cab signaling mechanism carried by the cab and adapted to give a single indication indicating procoed, and means along the traokway for actuating said signaling mechanism when the car or train approaches a home or distant position and the corresponding block is clear, whereby the rEa-il-ure to receive a proceed indication indicates to the engine man to proceed at caution or to stop the train depending upon whether the train is approaching a distant or home position.

3. In :a railway signal system, a trackway divided into blocks, means for indicating the home and distant positions along the trackway with respect to each block, a cab signaling mechanism on the cab, and means along the trackway for controlling said cab signaling mechanism, the signal received in the cab being the same when a train approaches a home or distant position whereby such signal indication in the cab must be interpreted in accordance with whether the train is approaching a home or a distant position.

4. In a railway signal system, a trackway divided into blocks, stationary home and distant markers for each block spaced along the trackway, a cab signaling mechanism on the cab adapted to give a single indication, and means along the trackway for actuating said cab signaling mechanism when the car or train approaches a home or distant marker, said signal indications being the same when approaching a home or distant marker and are interpreted in accordance with whether the train is approaching a home or a distant marker.

5. In a railway signal system, a trackway divided into blocks, a home and distant marker for each block, a cab signaling mechanism on the cab adapted to give a single positive indication indicating proceed, and means along the track-way for actuating said cab signaling mechanism only when the car or train approaches a home or distant marker and the block corresponding to the said marker is clear.

6. In a railway signal system, a trackway divided into blocks, a home and distant marker for each block, a cab signaling mechanism adapted to give a single cab indication indicating proceed, and means along the trackway for actuating said cab signaling mechanism when the car or train approaches a home or distant marker and the block corresponding to said marker is clear, said means along the trackway comprising track signal circuits and control circuits, said cab signaling mechanism comprising a cab signal circuit, said cab signaling mechanism being adapted to be actuated only when the cab signal, track signal and control circuits and the cab signal circuits are in closed condition.

7. In a railway signal system, a trackway divided into blocks, home and distant markers for each block, a contact rail to the rear of each marker, a cab signal circuit carried by the cab adapted to engage said contact rail to close said cab signal circuit a track signal circuit for energizing said contact rail and track control circuits for said track signal circuits adapted to close said track signal circuits when energized, track relays for controlling the track control circuits arranged to close said track control circuit when the track section connected to a track relay is clear, a cab signal in said cab signal circuit adapted to give a single positive indication indicating proceed,

whereby when the cab approaches a home or distant marker and a positive indication is given, the engine-man is informed that he may proceed at full speed and the failure to receive a positive indication on approaching a home or distant marker indicates to the engine-man that he is to stop his train or to proceed at caution respectively.

8. In a railway signal system, a trackway divided into blocks, stationary home and distant markers for each block spaced along the trackway, a signaling mechanism on a vehicle, and means along the trackway for actuating said signaling mechanism when the vehicle approaches a home or distant marker.

9. In a railway signal system, a track- Way divided into blocks, stationary home and distant markers for each block spaced along the trackway, a signaling mechanism on a vehicle, and means along the trackway for actuating said signaling mechanism to give the same indication in the vehicle when it approaches a home or distant marker, which signal is interpreted by the person in the vehicle in accordance with whether the vehicle is approaching a home or a distant marker.

In witness whereof, I subscribe my signature, in the presence of two witnesses.

ROBERT J. I-IEWE'IT. Witnesses:

WALDO M. CI-IAPIN, JULn E. ZELENKO.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

